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Tentaculites

Tentaculites
Temporal range: Early Ordovician – Late Devonian
TentaculitidDevonian.jpg
Tentaculitids from the Devonian of Maryland.
Scientific classification
Kingdom: Animalia
Phylum: Mollusca (?)
Class: Tentaculita
Order: Tentaculitida
Family: Tentaculitidae
Genus: Tentaculites
von Schlotheim 1820

Tentaculites is an extinct genus of conical fossils of uncertain affinity, class Tentaculita, although it is not the only member of the class. It is known from Lower Ordovician to Upper Devonian deposits both as calcitic shells with a brachiopod-like microstructure and carbonaceous 'linings'. The "tentaculites" (i.e. tentaculita) are also referred to as the styliolinids.

The taxonomic classification of tentaculitids is uncertain, but some group them with pteropods. They may also be related to other conical shells of uncertain affinity including cornulitids, Anticalyptraea, microconchids and trypanoporids. Their shell microstructure has warranted their comparison with the brachiopods and phoronids.

Tentaculitids have ribbed, cone-shaped shells which range in length from 5 to 20 mm. Some species septate; their embryonic shell, which is retained, forms a small, sometimes spherical, chamber.

Some species are inferred to have been planktonic.



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